Apparatus for attaching a hose to a fitting

ABSTRACT

A hose coupling for use with flexible hose comprises a biconical fitting which is inserted into a hose end and a frusto-conical locking sleeve located about the hose portion which grips the rearward conical section of the fitting. Sealing arrangements for specific embodiments of hose are disclosed. 
     The double included angle of the conical portion of the sleeve and fitting, which engages the hose, is between one degree but less than ten degrees.

BACKGROUND AND SUMMARY OF THE INVENTION

This is a continuation application of U.S. patent application Ser. No.189,395, filed on May 2, 1988, now abandoned which is a continuation ofU.S. patent application Ser. No. 066,749, filed on June 23, 1987 nowabandoned.

This invention relates to a method and apparatus for attaching hoses andtubes to a fitting and more particularly to a specially configured, handassembled, tube coupling and apparatus.

Attaching hoses and tubes to fittings to form a reliable fluid-tightcoupling has presented problems over the years. Two basic problems areaxial pull off (separation of the hose from the fitting) and pressure orvacuum sealing of a confined media. Hose clamps, crimped on ferrules,and attachments that screw on and in the hose can provide an effectivemethod of terminating a hose but they can be complex, expensive tomanufacture, and involve special tools to assemble.

A fitting having both conical and double-conical shapes (i.e., diamondshaped) in combination with a frusto-conical locking sleeve have beenused to terminate a hose. Generally, the hose is thrust over the largediameter of the cone and seated about the reverse tapered portionthereof. For one reason or another this type of hose coupling has notbeen totally reliable and this is not generally used commercially. Forexample, to resist axial pull off prior, terminations have made theangle of the reverse taper greater than needed. When a hose is thick orits material is stiff and unyielding, advancing the outer sleeve by handis so difficult that the result is inadequate pressure exerted on thehose by the outer sleeve.

To improve the hose connection utilizing the double conical fitting, ithas been believed by others in the art that special arrangements arerequired for driving the sleeve relative to the fitting. Deutsches Reich424980 (1926) provides a spring for driving an interiorly threadedsteeve onto the hose. These threads are at a different taper than thatof the sleeve or fitting and bite into the outside of the hose tocompress the sleeve about the hose and the hose about the fitting,thereby retarding loosening or pull-off of the hose from the fitting.Dutch Patent No. 27183 (1932) provides a coupling nut which isthreadably advanced about the sleeve in a direction that drives theouter sleeve up onto the fitting and about the hose to increase thepressure between the hose and fitting.

The angle range is particularly important because the mechanicaladvantage of the sleeve capability decreases with increasing angle. Whenone uses a separate driving nut, one only has the mechanical advantageof the thread at initial installation or retightening.

It would be desirable to provide a coupling wherein a threadless outersleeve could be easily set or engaged by hand, thereby eliminating thepossible need for torquing the outer sleeve. With a proper angle rangeonly very rudimentary means of preventing tube or hose "push back" orsleeve securement are required.

Accordingly, there is provided herein a hose coupling for terminatingthe end of a deformable hose or tubular member, which coupling includesa tubular fitting having an exterior surface and adapted to be receivedinteriorly of the hose and a frusto-conical locking sleeve having aninterior surface and adapted to be circumposed about the hose wherebythe hose is clampingly secured between the surfaces of the fitting andsleeve. Further, the fitting includes a forwardly extendingfrusto-conical portion which defines a lead-on area at the end of thefitting. In particular, the hose engaging surfaces are frusto-conicalwith the angles defining each cone being limited to a narrow specifiedrange. In accordance with this invention the frusto-conical surfaces aredefined by a taper angle of between 1/2 degree to 4 degrees per siderelative to the fitting axis. (i.e., the frusto-conical surfaces definea 1° to 8° double included angle.)

The prior art fails to recognize that the included conical angle of thehose engaging surfaces be small and be from about 1/2 degree per side to4 degrees per side. Unexpectedly, this specific angle range produceslocking and sealing results that are so outstanding that threads andsprings, etc., are not necessary for the same reliability. Selection ofthe special angle range resists any relative movement of between thesleeve, hose, and fitting that could loosen the mechanical lock on thereverse taper or disrupt the pressure sealing integrity of theattachment. A fitting so configured allows the use of an outer sleevethat is very simple, requires only minimal force to compress the hoseabout the fitting, and is spaced away from the hose sealing area yetprovides an additional locking of the hose to the exterior of thefitting. All of this may be accomplished by hand setting of the outersleeve.

It is believed that if the angle defining the frusto-conical sealingportion is greater than the above-noted specific range, very minordistortions of wall thickness will result in greater loss of sealing.Since the reliability of the attachment is also determined by how wellit seals over time, angles larger than those specified herein arebelieved to cause a more rapid deterioration of sealing. Also, theselarger angles require more distortion of the hose or tube material bywhat is termed secondary locking means that are incorporated on theinner member. The more rapid deterioration of the tube or hose materialthat results also contributes to rapid loss of sealing.

Further, in accordance with this invention, there are disclosedintermediate adapter elements between the locking sleeve and hose and/orbetween the hose and fitting. Specific of these elements are not wedgeshaped but are also defined on their interior and exterior surfaces bythe same double included angle of between 1 and 8 degrees, whereby tofollow the respective interior surface of the locking sleeve or exteriorsurface of the fitting. The purpose of these adapter elements is todistribute stresses and assist in sealing, each typically being of asuitable elastomer. An advantage of reducing stresses is an increase inhose life.

Accordingly, there is provided herein a hose coupling including afrusto-conical fitting and sleeve lock which cooperate to resist pulloff as well as having (a) resistance to the temperature caused changesthat result in loosening or leaks, (b) resistance to the vibrationcaused changes that result in loosening or leaks, and (c) resistance tomechanical forces that push on the tube or hose in a manner that"unlocks" the sleeve lock, or encourages leaking.

The interaction of all these factors generally stems from the fact thatthe hose or tube is spring like, and depending on its mass and/ordeformation recovery characteristics, the hose or tube will exhibitresonances of mechanical motion. One component of this mechanicalmovement are forces developed in an axial direction which tend to unlockthis type of attachment. Temperature effects affect the resistance tothese and other unlocking mechanical forces.

Advantageously, the specially configured outer sleeve fitting provide alow cost coupling, and the labor expended in "setting" the outer sleeveis definitely lower cost than setting clamps, crimping ferrules, orscrew-over type attachments used in some cases to replace crimpedferrules.

A variety of different types of pressure or vacuum confining conduitsare shown and described herein. The foregoing and other advantages willbecome more apparent when viewed in light of the accompanying drawingsand the following detailed description wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view in cross-section of a fluid-tightcoupling comprising a hose clamped by a sleeve about a tubular fitting;

FIG. 2 is side elevation view, partially in section, of an alternateembodiment of a fluid-tight coupling according to this invention whereina biconical fitting is used to terminate oppositely extending hoses;

FIGS. 2A and 2B provide detail of the left end hose coupling shown inFIG. 2;

FIG. 3 is a perspective view of an alternate embodiment of a fluid-tightcoupling according to this invention including an arrangement forgripping the hose;

FIG. 4 is a side elevation view, in cross-section, of the coupling shownin FIG. 3;

FIG. 5 is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this invention showinga redundant seal;

FIG. 6 is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this invention showinga redundant seal;

FIG. 7 is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this inventionincluding redundant elastomeric sleeves which clampingly engage acorrugated hose;

FIG. 8 is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this invention showinga corrugated hose;

FIG. 9 is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this invention showinga redundant seal;

FIG. 10 is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this invention showinga low pressure cup seal;

FIG. 11 is a side elevation view, in section, of an alternate embodimentof a fluid-tight coupling according to this invention, showing theincorporation of a seal between the fitting end and conduit interior,and means for strengthening the fitting end;

FIG. 12A is a side elevation view, in cross-section, of an alternateembodiment of a fluid-tight coupling according to this invention,showing a serpentine-shaped sleeve clamped about the fitting; and

FIG. 12B is a perspective view of the serpentine-shaped sleeve shown inFIG. 12A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to the drawings, FIGS. 1-12 show fluid couplings eachgenerally comprising a biconical fitting, a locking sleeve disposedabout the fitting and at least one tubular hose or conduit 10 clampinglysecured to the fitting by the sleeve. The forward end portion of hose 10is pushed onto a frusto-conical lead on entry defining an open end ofthe fitting, over a crest and onto a reverse frusto-conical portion andheld thereto by the clamping or gripping action of the outer sleeve.Various embodiments of hose connections and gripping arrangements aredisclosed herein.

The tubing or hose 10 is representative of single or multiple wall,reinforced, or not-reinforced generally routable, not rigid metal,construction for use in fluid installations, such as hydraulic orpneumatic equipment. Hose 10 consists of a material that is deformableto an extent, but not (or only slightly) compressible. In other words,not a foam which is compressible because of its porosity or trapped gaswhich is compressible. Hose 10 is generally axially extending havingconcentric outer and inner surfaces 12 and 14 and a forward end 16 cutsquare, the inner surface defining a central bore 18 to confine and passthe fluid.

FIG. 1 shows a fluid coupling formed along an axis "A" wherein theforward end portion of hose 10 is coaxially sandwiched between generallyaxially extending tubular fitting 20 and outer lock sleeve 22. Fitting20 has an axial bore extending therethrough and generally comprises acylindrical body member 24 from which a hose terminating biconicalportion 26 extends, the biconical portion including a first and a secondend portion 28 and 30, each end portion being generally frusto-conicallyshaped. The respective exterior surfaces of portions 32 and 34 areconical and defined by a double included angle "B" and "C" relative toaxis "A" and intersect at a crest 32 defining the largest diameterportion which expands the hose. Generally, cylindrical body member 24 isa portion of some device such as a rigid pipe, a fluid connector, orsome attachment which passes the fluid confined by hose 10. End portion30 defines a lead-on area for receiving the and expanding the hose endportion and end portion 28 defines a reverse taper surface for the hoseto grip. Fitting 20 would preferably be constructed of rigid material,so as to resist diametric reduction during the life of the attachmentsuch as steel, brass or an oriented organic fiber.

Outer sleeve 22 is generally frusto-conical in cross-section and itsinterior wall is conical for gripping the hose exterior and is formed bya double included angle "D" relative to axis "A". Sleeve 22 includesforward and rearward end portions 34 and 36 at its opposite ends.Rearward end portion 34 defines a radial flange 34 extending radiallyoutward from the sleeve to assist the user in coaxially driving theouter sleeve relative to hose 10 and body portion 28 of fitting 20 overwhich sleeve 22 is located whereby to lock the outer sleeve relative tothe hose and fitting. Preferably, forward end portion 36 is outwardlyflared and extends to a point equal to or forwardly of crest 32 betweenfrusto-conical end portions 28 and 30 when the outer sleeve is locked tothe hose, the extended portion (or overhang) assisting in the inwardinsertion of the hose end portion, the positioning of the sleeve, or insupporting the hose in situations where the hose is bent adjacent thefitting end. Preferably sleeve 22 is made from some material that hasband strength and resists diametric expansion during the life of theattachment, such as steel, brass or an oriented organic fiber material.

In accordance with this invention, it has been found that the doubleincluded angle "B" for the exterior frusto-conical surface portion offitting, and "D" for the interior surface of outer sleeve 22 are veryimportant to achieving the unexpected results that improve thereliability of the attachment to an extent it that is commerciallydesirable. Specifically the double included angles "B" and "D" of thesefrusto-conical surfaces should be nearly matched, and preferably bebetween one degree and eight degrees (i.e., a taper angle of about 1/2degree to less than 5 degrees per side). These small double includedangles "B" and "D" result in a tremendous "mechanical advantage" whereinforces applied to sleeve 22, to "drive" the sleeve towards the largestdiameter at crest 32 and into engagement with conduit 10, are multipliedmany times to result in extremely high capturing or clamping forcesbeing applied to conduit 10. Surprisingly so, the small conical anglesresult in relatively small discontinuities in the conical surfaces offitting 20 and sleeve 22 which contact the surfaces 12 and 14 of conduit10 requiring a much larger force being applied in order to disrupt thesecured relationship of conduit 10, fitting 20 and sleeve 22.

There are situations with constructions of conduit 10 where it is verydifficult to expand the diameter of conduit 10. In order that conduit 10be hand assembled over the largest diameter of fitting 20 at the areawhere the reverse taper portion 28 meets the lead on portion 30, it isnecessary to limit this largest diameter. To gain extra retention it isconvenient to slightly reduce the free diameter of conduit 10 at theroot or smallest diameter of reverse taper area 28. In every case sincethe surface area of portion 28 is tapered, there will be a smallest andlargest diameter. The wall thickness of conduit 10 will be slightly lessat the largest fitting diameter than it would be at the smallestdiameter of portion 28. Since the largest "footprint", that is thesurface area of conduit 10 captured between fitting 20 and outer sleeve22, is desirable in order that stresses on the material of conduit 10 beminimized by having the capturing force distributed over a large area,it is necessary that double included angle of the outer sleeve besomewhat less than the double included angle of the fitting. Thisdifference is dictated by the variation in thickness of conduit 10. Itis possible to make a workable attachment using angle "B" equal to oreven slightly less than angle "D", because of the unusually tolerantsituation that is achieved when angles between one and four degrees areused, but best results are obtained from a longevity standpoint byminimizing the stresses on the material of conduit 10.

It will be found to be advantageous to dimension sleeve 22 in a mannersuch that in the maximum tolerance condition where the dimensions aresuch that the sleeve 22 moves at the least an amount over lead onportion 30, and that sleeve 22 contact area with conduit 10 bepositioned so as to be in contact with the conduit 10 at the area ofgreatest diameter of fitting 20. Secondary locking means serve to assurethat the positional relationship of conduit 10 relative to fitting 20and sleeve 22 is secured throughout the service life of the attachment.Generally, as the hose tends to be pulled off the biconical fitting, theouter sleeve follows the hose to further tighten the joint. The lockbetween the hose and sleeve could in some applications be limited to thesmall half of the sleeve and operable directly on the outer portion ofthe hose (or outer portion of an intermediate element positioned betweenthe exterior of the hose and the interior of the sleeve) so that thestresses imposed have a minimal effect on the stresses involved insealing and retention.

In the embodiments shown in FIGS. 2-12 the respective sleeve andfittings use the same matched angles "B" and "D" to achieve the sameresult. Elements that are the same as previously described will bemarked with the same reference number. The embodiments to be discussedwill respond to surface shape and conditions that are common to variousconduits 10, and the use of a separate sealing means to seal the conduitto fitting 20 which is used in conjunction with the attaching means. Forexample, an interposed seal is necessary when the inner surface of theconduit is not smooth enough to make an adequate seal.

FIG. 2, 2A and 2B show a hose coupling wherein both ends of cylindricalbody member 24 will be used to receive, each, a hose 10a and 10b, thebody member having a cylindrical annulus 38 which defines a stop. Eachend of body member 24, designated with the letters "a" and "b",respectively, when considering the left or right extending end, isprovided with a biconical portion 26a and 26b including first and secondend portions 28a and 30a and 28b and 30b, respectively, to receive onerespective hose 10a and 10b. A frusto-conical clamping member or locksleeve 22a and 22b is located about the respective hose end portion andend portion 28a and 28b. The respective inner surfaces of sleeves 22aand 22b and exterior surfaces of conical end portions 28a and 28bclampingly grip the respective hose 10a and 10b end portion. Thefrusto-conical angles "B" that describe exterior surfaces of endportions 28a and 28b and "D" that describe interior surfaces of sleeves22a and 22b would be defined by the double included angle of between 1°and 8° relative to center axis "A".

Sleeve 22a would be manufactured with a flange 40 partially turnedinward, flange 40 being bent radially inward to allow sleeve 22a to beloosely attached to fitting 20a. Sleeve 22a is located onto fitting 22aprior to pushing conduit 10a up over fitting 22a. By making flange 40 sothat conduit 10a is not stopped by sleeve 22a as it is pushed ontofitting 20a, conduit 10a will merely centralize sleeve 22a as conduit10a is pushed on. After assembly of sleeve 22a over fitting 20a, theinward forming of flange 40 would be completed. This would then looselysecure sleeve 22a to fitting 20a, so that the resulting assembly wouldbe ready to use in the field. The flared portion 36a and 36b would beprovided on sleeves 22a and 22b.

Means of assuring the positioning of the parts throughout the life ofthe attachment include provision of a slot 42 at the turned intransition of flange 40, slot 42 providing an area where the material ofconduit 10a can bulge up into the slot 42 after the distortion ofconduit 10a that results from locking or "setting" sleeve 22a to effectthe attachment of conduit 10a to fitting 20a. Because of the large"footprint" (previously defined) of sleeve 22a, and the special angles"B" and "D", very large compressive forces are developed on conduit 10a,but only a small distortion of conduit results. Because of the specialsmall angles "B" and "D" however, very little material is required inshear (the bulged up portion of the material of conduit 10a) to effect avery robust locking of the position of sleeve 22a on conduit 10a.

Means to lock conduit 10a to fitting 20a include provision of one ormore raised portions on the surface of the reverse taper portion 28a offitting 20a. As shown, a raised area 44 to secure the position ofconduit 10a on fitting 20a is located from the minimum diameter area offitting 20a. Note also, that very little deformation of the material ofconduit 10a would be used so that stresses on conduit 10a would beminimized. Small "pinched up ears" on the surface of fitting 20a whichwould in effect be small segments of raised area 44 are effective. Theadvantage of this treatment is that the "pinching" operation on thefitting 20a results is small pockets adjacent to the "ears". Thematerial of the conduit 10a may thus be distorted into these pocketswhen displaced by the ears. This greatly reduces the force required tocause this distortion, and makes "setting" sleeve 22a easier and withless variability. The section extending to the right of body member 24shows includes an annular groove 46 which acts very much like the slot42 and sleeve 22b includes a raised radial groove or rib 48 that actsvery much like the raised area 44.

It is anticipated that in using the disclosed attaching method, thatsleeves 22a and 22b will be "set" by various means. These means wouldinclude "hand setting", and setting by means of simple tooling. Someusers may prefer a more visual mechanical means of setting with aneasily inspectable result.

FIGS. 3 and 4 show a fluid coupling wherein an alternate means of"setting" the sleeve are provided. Elements that are the same aspreviously described will be marked with the same reference number. Anarcuate slot 50 (similar to slot 40 in FIG. 2) has been formed in sleeve22 so that it frees a portion of outward radial flange 34. A flange 52is then provided to be employed as a bendable segment which drivessleeve 22 up on to engagement to lock conduit 10 about fitting 20.Flange 52 would be bent with an appropriate tool and because of thenature of the material of sleeve 22 act to urge sleeve 22 into a "set"position. The confirmation that sleeve 22 has been "set" could then bevisually accomplished by merely noting that flange 52 is in intimatecontact with device 24. As before, extrusion of the hose into slot 50assists locking of the hose relative to the coupling.

FIG. 5 shows a fluid coupling wherein conduit 10 has a rough outersurface. Elements that are the same as previously described will bemarked with the same reference number. To minimize the stresses appliedto conduit 10 in order to maximize its service life, a collar 54 ofdeformable material is sandwiched between the interior surface of sleeve22 and exterior surface 12 of the conduit. Collar 54 distributes theforces applied by sleeve 22 to the conduit 10 more evenly, thus reducingthe stresses developed in the conduit 10 from the compression forcesthat result from "setting" sleeve 22. The rough outer surface of conduit10 will "lock" material 54 into position. If desired, a slot 40 or 50may be used to lock outer sleeve 22 to the material of collar 54.Forward end of the sleeve would be flared at 36 and a reversely bentflange 56 which has a radially inward portion 58 to captivate the collarabout the hose and assist its movement during locking. A radial outwardportion 60 assists in driving the sleeve 22 relative to the hose. Thesleeve 22, collar 54 and fitting end portion 28 would be formed at thespecial double angle of about 1 to 8 degrees.

FIG. 6 shows a fluid coupling that is similar to the coupling shown inFIG. 5. Elements that are the same as previously described will bemarked with the same reference number. In this embodiment the inner wall14 of conduit 10 is not sufficiently smooth to be axially positioned, toproperly seal, or to reduce the stresses in the conduit. Interposedbetween the hose and end portion 28 of fitting 20 is a frusto-conicalband 62 comprised of a material that is more tolerant of conduitdeformation, so as to functionally survive the increased useful life.Fitting 20 is formed with a outward radial portion 64 to preventinterposed band 62 from being pulled off of the fitting 30. Preferablyband 62 would be preformed with the double included conical angle ofabout 1 to 8 degrees.

FIG. 7 shows a fluid coupling embodiment disclosing a further aspect ofthe embodiments discussed in FIGS. 5 and 6. Elements that are the sameas previously described will be marked with the same reference number.In this embodiment conduit 10 is formed by a corrugated material that isoften used for very low pressure applications, but which is not suitedfor the sleeve lock approaches heretofore described. Conduit 10 isinterposed between shaped sleeves 64 and 66, sleeve 64 being inner andsleeve 64 being outer to the conduit, the sleeves 64, 66 beinginterposed between the lock sleeve 22 interior frusto-conical surfaceand fitting 20 exterior frusto-conical surface, the sleeves 64, 66 beingconical with their double included angle being between one and eightdegrees and substantially matching the inner and outer surfaceconfiguration of conduit 10. A very low stress is developed in conduit10, which greatly extends the service life of the conduit. If theprojecting portions 68 and 70, from the respective sleeves 64, 66 arehelically wound, and the corrugations 72 are helically wound, each meshtogether and rotation tightens the coupling.

FIG. 8 shows a "Greenfield" type conduit 74 comprising a liner conduit10 and a rugged outer conduit 76 to provide mechanical strength in and asealed relationship with the fitting 20 with the required mechanicalintegrity to be useful for high pressure applications. Conduit 74 thathas been assembled over fitting 20 and into sleeve 22 and "set" orlocked as previously described. Mechanical strength outer conduit 76 hasbeen compressed back (it is spring like) during this operation. Ferrule78, having an outward flare 82 forwardly of the crest 32 and having beenfirst assembled over fitting 20 along with sleeve 22, is used to drivesleeve 22 into its locked position by inward flange 80 of ferrule 78driving outer flange 34 of lock sleeve 22. The interior of outer conduit76, being larger in diameter than the diameter of flange 34, passes overflange 34, and the end of conduit 76 drives ferrule 78 back againstdevice 24 when it engages inward flange 80. Ferrule 78 is then crimpedadaptively around the inner form presented by conduit 76, flange 34 andsleeve 22 by means of adaptive crimping die shoes that are made fromsome deformable material-like rubber or urethane. Ferrule 78 thusmechanically secures conduit 76, which is additionally engaged to flange34 of sleeve 22, and further drives sleeve 22 into further engagementover inner liner conduit 10 to additionally secure and seal conduitliner 10 to fitting 20. Note that now inner conduit liner 10 is nolonger required to withstand the blow-out forces of high pressure ortemperature effects that might weaken conduit 10, since a slightexpansion of conduit 10 is immediately limited by the very strong andtemperature resistant outer conduit 76. Outer conduit 76 would bemanufactured from metal (as an example of a suitable material) and thusinner conduit 10 may be made from a material-like plastic that does nothave the mechanical properties at high temperatures that are necessaryfor the outer conduit 76, and the required high pressure and temperatureperformance. The combination of conduits will thus operate attemperatures in excess of the capability of conduit 10 alone.

FIGS. 9 and 10 are for situations wherein the redundant sealingcapability would comprise a "dinamic" type seal which exerts moresealing pressure in response to an increase in pressure. In accordancewith this invention the dynamic seal would be placed forward of thestatic seal, such as described in the preceding embodiments. A benefitof the forward location, in conjunction with the sleeve lock-typeattachment, is that less "penalty" in interior diameter through theattachment is encountered. The forward attachment will offer an improved(static) compression seal which will easily out perform in time theknown static compression seals that are used because of "largefootprint" and low deformation percentage, but will also offer the addedbenefits to be derived from the use of a dynamic seal. There is adefinite need to be able to get extended service life, and to be able tosafely employ the otherwise superior plastic piping that is availabletoday.

FIG. 9 shows a fluid coupling wherein fitting 20 has near its hosereceiving terminus an inward radial recessed channel 86 sized to receivetherein elastomeric seal 84. The depth of the channel is such that seal84 projects above the periphery of the fitting end portions 28 and 30.The seal is shown as an O-ring, and acts as an additional seal to sealthe hose against the fitting end portions.

FIG. 10 is a fluid coupling useful in situations where extremely lowpressures are to be confined for periods of time that are long comparedto the creep properties of an elastomeric O-ring similar to that shownin FIG. 9. The coupling includes an inward radial recessed channel 88shaped to receive a "U" cup or "lip" type seal 90 comprised of metal.U-shaped seal 56 better utilizes the confined pressure to develop sealcontact force.

FIG. 11 shows a fluid coupling wherein the fitting is modified toinclude a nipple 92 formed of plastic having an axial bore 94therethrough and a metal sleeve 96 positioned within the bore. Outwardradial flanges 98 and 100 from the sleeve serve to couple the sleeve 96to the nipple such that the bore wall fits snugly about the nipple. Anannular groove 102 is formed between a step 104 in the nipple and raisedflange 100 on the sleeve, the groove sized to receive an elastomericO-ring 106 that projects about the periphery 108 of the nipple to be incontact with the inner wall 14 of hose 10. The nipple and sleeve aremanufactured as a portion of device 24. Sleeve 22 operates as previouslydescribed, and embodiments shown in other figures might also be employedhere, as they might be with any of the other embodiments shown in thevarious figures. The purpose of fitting end portion 30 is to provide alead area 34, allow O-ring groove to be easily provided in manufacture,and to strengthen tapered central portion 110 of the fitting sleeve. Onewould select metal as the material for sleeve 96 if device 24 were madefrom a material which would not resist the compressive forces (appliedby sleeve 22) over a long period of time for example. Conversely, if thematerial of device 24 were metal which would have the desired strength,then sleeve 96 portion might be made of plastic.

FIGS. 12 and 12A show a coupling similar to FIG. 1 wherein a serpentineformed frusto-conical sleeve 112 is disposed about the fitting. Sleeve112 is generally stamped from a flat sheet of metal stock with axialslots 114 extending inwardly from opposite edges 116 and 118 of thesheet but end short of the opposing edge. The slot radial widths aresuitably dimensioned to allow the sheet to be rolled into afrusto-conical shape, whereupon the adjoined edges are joined.Resiliency of the cone to accommodate rough surfaced hose and could beprovided by keyhole 120 enlargements at the root of one or more of theslots. End 36 is overhung beyond crest 32 connecting frusto-conical endportions 28 and 30. The interior and exterior surfaces of the sleeve 112and fitting 20 are provided with the special double included conicalangle of 1 to 8 degrees.

From the foregoing figures and explanations, it is seen that the sleevelock concept is adaptable to many variations of conduits. The sleevelock concept is commercially viable because of the recognition thatthere is a small range of angles, that when used, provide a dramaticimprovement in retention and sealing that make a commercially reliable,and therefore acceptable device possible. The inherent low cost of thereverse taper locking means has made such a device be recognized aspotentially commercially attractive for years, but previous attempts toprovide such a device always failed because those who were attempting todevelop and market such a device failed to comprehend the special smallrange of angles, that make such devices commercially acceptable, is anecessary precedent to achieving that goal.

While the above description constitutes the preferred embodiment of theinvention, it will be appreciated that the invention is susceptible tomodification, variation, and change without departing from the properscope or fair meaning of the accompanying claims.

What I claim is:
 1. A hose coupling for terminating the end of adeformable hose or tubular member, comprising a fitting having an endadapted to be received interiorly of said hose and to expand theinterior diameter of said hose when inserted therein, said fitting endhaving a smooth uninterrupted external surface to contact with theinterior surface of said hose, a biconical shape with a first and secondportion generally frusto-conical shaped and intersecting at a crestdefining a largest diameter portion of said fitting for expanding saidhose, and a locking sleeve having a smooth uninterrupted internalsurface to contact with said hose, said locking sleeve locatable oversaid hose whereby to clampingly secure the hose between the fitting andsleeve, said fitting and sleeve are constructed such that a portion ofeach is formed with a matching frusto-conical surface defined by adouble included angle of one to eight degrees the conical surfacesincreasing in diameter toward the inserting end of said fitting, saiddouble included angle of said sleeve being less than the double includedangle of said fitting, and said sleeve and fitting are sole meansretaining, sealing and positioning said hose between said sleeve andfitting.
 2. The hose coupling as set forth in claim 1, furthercharacterized by means provided between said locking sleeve and fittingfor locking said sleeve to the exterior of said hose, said means beingsubstantially smooth surfaces mated together in a friction-fitconnection.
 3. The hose coupling as set forth in claim 1, wherein saidlocking sleeve extends axially beyond the largest diameter of saidfitting.
 4. The hose coupling as set forth in claim 1, wherein saidfitting includes a second frusto-conical portion at the end thereof,said second frusto-conical portion being beyond the largest diameter ofthe first portion thereof and having a diameter which is smaller thanthe largest diameter of said fitting.
 5. The hose coupling as set forthin claim 4, wherein said smaller diameter is less than the insidediameter of said hose.
 6. The hose coupling as set forth in claim 1,wherein said locking sleeve includes a radially outwardly directedflange portion for driving said locking sleeve towards the largestdiameter of said fitting.